Lilith Zschetzsche, Robert Zillich,
"Suppression of polaron self-localization by correlations"
, in Physical Review Research, Vol. 6, 2024
Original Titel:
Suppression of polaron self-localization by correlations
Sprache des Titels:
Englisch
Original Kurzfassung:
We investigate self-localization of a polaron in a homogeneous Bose-Einstein condensate in one dimension.
This effect, where an impurity is trapped by the deformation that it causes in the surrounding Bose gas, has been
?rst predicted by mean-?eld calculations, but has not been seen in experiments. We study the system in one
dimension, where, according to the mean-?eld approximation, the self-localization effect is particularly robust
and present for arbitrarily weak impurity-boson interactions. We address the question whether self-localization
is a real effect by developing a variational method which incorporates impurity-boson correlations nonperturba-
tively and solving the resulting inhomogeneous correlated polaron equations. We ?nd that correlations inhibit
self-localization except for very strongly repulsive or attractive impurity-boson interactions. Our prediction for
the critical interaction strength for self-localization agrees with a sharp drop of the inverse effective mass found
in quantum Monte Carlo simulations of polarons in one dimension.
Forschungs-